Otto hoffman



(N0 Modem o. HOFFMANN.

@BINDING MILL.

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OTTO HOFFlvlr-XNN, OF ST. LOUIS, liilSSOUR.

UFECIFICATION forming part of Letters Patent No. 309,302,6.ated December 16, 188%.

Application tiled Julie 1l, 1891.

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1 0 @ZZ whom it may concern:

Be it known that l, Or'ro HOFFMANN, oi the ful Improvements in Grinding-Mills, of which the following is a speciiication.

This invention has reference to an improved grinding-mill in which the, runner is supported on a stationary spindle and driven by the hub of a power-transmitting pulley, and the invention consists of a grinding-mill the runner of which is supported by its balancerynd on a center pin of an intermediate guidecylinder that is connected by a clutch device with the hub of the driving-pulley. The top plate of the intermediate cylinder rests on the eockhead of a fixed spindle whieh'is vertically movable in its step-traine by a wornigear, so as to adjust the runner toward the bed-stone.

In the accompanying drawings, Figure 1 represents a vertical central section of my iniproved grinding-mill, and 2 is a detail horizontal section on line fc m, Fig. l.

Similar letters of reference indicate corre'- sponding parts.

Referring to the drawings, p represents the hed-plate of iny improved grinding-mill, to which are attached vertical standards n, for supporting the ring on, which. is provided with discharge-spout m.

On the flanged upper edge o" the ring m is supported the stationary upper niillstone, A, by an exterior ring, Z, and screw-bolts Z. By means ofthe set-screws Z the niillstone A. can be adjusted higher or lower, as required.

Between the exterior rings, in. and Z, a vertical guard-ring,Z2,is interposcd,wliieh prevents the flour from escaping, and which also adniits of the vertical adjustinent ol" the upper ring, Z.

To the bed-plate p is centrally attached a hollow step-frame, c, which is of heinispherical forni at its base and of cylindrical shape at its upper part. A fixed spindle, a, extends through the upper cylindrical part of the step-traine c, which spindle can be raised or lowered by an adjusting worin-wheel, j", and worin-shaft f, located in the lower part of the hollow step-frame c. The spindle a is prevented from turning aria-ily by a screw, s,

(No model.)

which engages a short groove, s, of the spindle a. llhe lower end of the spindle a is threaded and guided in a nut of the Werniwlieel, f. The spindle' a is provided at its upper end with a cock-head, g, which is secured by a ixed socket, 71, into the recessed upper part of the spindle. The top plate, e, of a guide-cylinder, c, rests by a cock-eye on the cock-head g. The lower end of the guide-cylinder c engages by clutch-connection q the hub b oli' a driving-pulley, ZJ, which turns loosely on the upper cylindrical portion o1" the step-traine c. The guide-cylinder el is centered. on the fixed spindle g by ineans oi' box-wood or Babbitt-metal bushes 1i, and by intermediate packing, v7, located in spaces between the recesses for the spindle-bushes, as shown in Fig. 2. The box-wood bushes t' are adjusted by ineans of set-screws The top plate, c, of the guide-cylinder e is provided with eonieally-tapcring center pin, e2, on which is placed the balance-rynd e of the lower niillstone or runner, B, said balancerynd being secured to the niillstone in the usual manner. The balance-rynd e is convex at its upper surface, so as to shed the grain or other articles to be ground to the narrow space between the grinding-surfaces of the stones, as shown in Fig. l.

Rotary iuotion inay be transmitted to the runner by gear-wheels instead of pulley and belt, and the lower stone be used as the bedstone and the upper stone as a runner.

The advantagesvof iny improved grindingniill are, first, that the entire niill can be shipped mounted ready for use; second, that the runner is not injuriously aiicected by the pressure ,oli the belt ol' the driving-pulley; third, that the horizontal position of the runner can be accurately adjusted by ineans of the box-wood bushes, so as to perform effectively its work in connection with the upper stone, A. and, finally, that the inill runs better in oil, as all the working parts are inclosed and protected against the settling of dust.

Having thus described iny invention, I elaiin as new and desire to secure by Letters Patent-u e l. The combination of aiixed vertical spindle, a step-frame supporting said spindle, a

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driving-pulley turning loosely on said stepa driving-pulley, clutch mechanism for con-V necting said guide-cylinder with said driving-pulley, a top plate provided with a center pin and turning on the cook-head of the iXed spindle, a runnerstone, a balance-rynd supporting said runner and turning on the center pin of the top plate, and a verticallyadjustable bed-stone, substantially as set forth.

3. The combination of the bed-platep, stepframe c, having lower arched and upper cylindrical portions, vertical spindle a, having threaded lower part, worm-Wheel f', having threadedhub engaging the threaded portion of the spindle, Worm-shaft f,` and the pin s, and slots', substantially as and for the purpose described.

4. The combination of the pulley b, guidecylinder e', mechanism for connecting said cylinder with said pulley, adjustable bushes i, interposed packing i', and the spindle a, substantially as described.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing Witnesses.

OTTO HOFFMANN.

Vitnesses:

PETER MERKEL, ROBERT GRUFELT. 

